JPS59181303A - Multifilament composite material and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing multifilament composite materials, particularly for use as reinforcing members.

Description of the Prior Art Strengthening members are used in a wide variety of applications, including cables such as those for telecommunications. For example, the light guide cable sheath provides mechanical protection and tensile stiffness for the optical fiber. Increasing the tensile stiffness is desirable to obtain high tensile load ratings without exceeding the fiber's maximum strain tolerance. A good example is that described in US Pat. No. 4,241,979. In the cable of this patent, two layers of stainless steel wire, each embedded with high density polyethylene (HDPE) K, are helically wound to form a reinforcing member of the orthogonal thin layer sheath. The unreinforced HD, PE sheath shrinks about 6 percent along its longitudinal axis during coating. If this shrinkage is not suppressed, fiber microbending losses will increase. The steel wire provides the necessary compressive stiffness for this shrinkage control.

However, in many applications it is desirable to have an all-dielectric reinforcement member. A reinforcing member suitable for this purpose must have a combination of high tensile and compressive stiffness. Those that meet high tensile strength requirements include unimpregnated fiberglass rovings (low or no twist fiber bundles) or aromatic polyamides (eg E.I. Dupont fLI).

Dupont) KEVLER
) Yarn However, since these have a yarn-like structure, they have low compression stiffness.

The yarn-like or roving-like filaments bend without stiffening under the compressive loads that occur during cooling of the HDPE sheath. The result is a region of low initial tensile stiffness or "knee J" in the stress-strain response of the cable, which is contrary to the design intent of the reinforcing sheath.

Continuous filament fiberglass rovings not only have high tensile stiffness, but are also non-conductive, inexpensive, have a coefficient of thermal expansion compatible with optical fibers, and do not lose their mechanical properties at cabling temperatures. Therefore, it is an excellent candidate material as a reinforcing member. However, to obtain the desired compressive stiffness, the rovings must be impregnated to promote bonding between the filaments. KEVLER yarns are also nonconductive, but for use in light guide cables and the like, they require increased compression stiffness.

Commercially, the impregnation of E-glass (alkali-borosilicate composition) rovings is carried out by pultrusion methods.

That is, the roving is passed through an epoxy resin bath and then introduced into a heated long mold to cure. Since the mold is long,
This method has a fairly slow C processing rate (about 1-2 meters/min) and is therefore expensive.

Attempts were made to extrusion laminate nylon to E-glass rovings, but research was not continued as the nylon was found not to penetrate the filament. Attempts have been made to coat multi-strand carbon fibers with UV-cured hyacrylic resins, but good penetration has not been achieved. The problem of coating multifilament bundles is in contrast to single fiber coatings, for which film application and radiation curability are known. For example, optical fibers are coated with acrylic epoxy resin, silicone, etc. and cured with ultraviolet light.

SUMMARY OF THE INVENTION The present invention relates to a method of manufacturing a composite multifilament member in which a multifilament bundle is impregnated with a coating liquid and hardened by exposure to actinic radiation. The fibers are usually glass or aromatic polyamide (and others may be used).

The coating liquid permeates the bundle and substantially surrounds each filament. A preferred coating liquid includes a bisphenol-A-diglycidyl ether diacrylate resin, (
B) aliphatic urethane resin (optional), and (1) a mixture of penta and cadrabucyl methylene glycol diacrylate, (J) 1.10-decamethylene glycol diacrylate, and (10 polyethylene glycol (200
) at least one diluent selected from the group consisting of dimethacrylates. The coating liquid can be a polydisperse layer selected to obtain a low wetting angle on the coated filament. A coated fiber bundle typically consists of at least 100 fisciments with a diameter of 20 micrometers or less. The method of the invention typically allows coating curing at a rate of at least 20 meters/minute.

Next, a radiation-curable liquid coating material is applied to the multifilament bundle and cured by exposure to radiation.
The details of the method for manufacturing the composite material will be explained.

The present invention is based on the recognition and discovery that with a suitable liquid coating, good impregnation and rapid radiation curability can be simultaneously obtained within a multifilament bundle. The roving impregnation process (RIP) of the present invention imparts the desired compressibility to the glass or KEvI, AR bundle.

The multifilament bundles are in the form of rovings (with little or no twist) or yarns (twisted bundles).

Faster processing speeds than pultrusion methods, ie, speeds in excess of 20 meters/min, are easily obtained. In order to objectively show this processing speed, other typical processing speeds related to full optical fiber manufacturing are shown below.

1. Roving drawing: 400 meters/min. 2. Optical fiber drawing: 60 to 150 meters/min. 3. Filament winding (formation of impregnated fiber glass solid phase part): 35 to 150 meters/min. 150 meters/min. 4. Pultrusion: 3 meters/min or less.

The materials used in the method of the invention are radiation curable coatings and multifilament bundles. To composite these materials, at least several hundred fine (1<20 ttm diameter) filaments are wetted with a liquid coating and the coating is cured to form a shear bond between the filaments.

A suitable coating material will have the following desirable properties:

1. Excellent filament wettability, and 2. Fast curing.

Furthermore, when used as a reinforcing member of an optical fiber cable coated with a high-density polyethylene (HDPE) sheath, the following characteristics are required.

3.H'DPE processing temperature (220C, resistance to deterioration of mechanical properties; 4.Crystallization temperature (120-130C), which ensures high compressive stiffness at which most HDPE shrinks; glass transition temperature below 20C; 5. Foam cage during HDPg extrusion molding (
Low weight loss at 2200 or less.

It is difficult to formulate a single resin system that exhibits good wetting and fast curing properties in the liquid state and good high temperature properties in the cured state. Diacrylic resins are suitable for obtaining high reactivity and rapid curing rates, while dimethacrylic resins exhibit acceptable properties. High-temperature properties can be obtained from bisphenol-A-diacrylate resin, but even if a multifilament bundle is impregnated with one layer of this resin, the coating speed will be much faster. none·. By properly selecting the diluent, the '4 overcuring process can be significantly improved. To speed up the impregnation of large multifilament bundles, it is necessary to reduce the equilibrium contact angle.

When carrying out the method of the invention, it is advisable to use a coating liquid that has an equilibrium contact angle of 20 degrees or less, preferably 10 degrees or less with respect to the filament used.

The contact angle of a coating is usually a nonlinear function of the contact angles of its components. In the case of binary mixtures, for example, Marcel Detzker & Co., New York
Prediction of mixture properties by L. E. Nielson (Arcel Dek'ker Inc.): Method of mixtures in Japanese science technology EIJ
(Prediet'ing the Property
iesof Mixtures:Mixture
Ru1es in 5eience and Eng
A semi-experimental approach can be used to approximate the resulting contact angle, as described in (1978). Additionally, multiphase coating liquids can be used in the method of the invention. This widens the selection range of components for obtaining a coating liquid with desired properties. For example, the above diluent (J) is not miscible with resin A,
Similarly, 1c8 diluent (I) is not miscible with any of the resins A and B. A mixture of these components provides good coating properties despite being an opaque dispersion medium in which light is substantially scattered.

By mixing urethane resin in addition to acrylic resin and one or more diluents, the composite has better flexibility.
For example, aliphatic urethanes are suitable for these purposes. Suitable urethane resins are described in U.S. Pat.
4.324. ' Described in No. 575.

Materials suitable for carrying out the present invention are shown in Table 3.

Table I Diluents (I) Mixture of penta and cadrabucyl methylene gelicol diacrylate 111) CH22CHC-0(CH2') -0-C-
CH=CH214,15 Sartomer Chemical Co., Ltd.
icalcompany) to Chemlink (Chem.
link) Available as 200.

(J) 1.10 decamethylene glycol diacrylate 111 SAR JL (SR) 287 from Sartomer Chemical Company
You can get it as 7.

()0 Polyethyl glycol (200) dimethacrylate 111 CHZ -CHCO(CH2' CH2o-) 4.5
-CCH-CI (2) Available from Sartoma Chemical Co. as Nissur (SR) 252.

Resins (A) Bisphenol-A-diglycidyl ether diacrylate CH3 In the formula 1. The components (excluding the photoinitiator) are preferably mixed in various weight percentages: A=40 to 76.3; B=0 to 33.2: I, J, and Kfl.
The above ratio can be achieved by diluting diluents I, J, and K alone or in combination. A suitable composition diagram is shown in FIG. When curing by ultraviolet radiation, a photopolymerization initiator is added, usually in an amount of 1 to 5 percent.

Similarly, by adding pigments, it can be colored as desired.

Commercially available fiberglass is coated with a focusing system that includes silane and a binder. The silane adheres to the glass via the silane group and to the coating IC via other terminal functional groups. The binder protects the glass during processing and melts into the coating to provide wettability. All of these components lower the separation energy of the glass. Amino- or glycidoxy-terminated silanes are widely used as binders in fiberglass rovings. The former is preferred for polyester and epoxide-terminated matrix materials, while the latter is preferred for epoxide-terminated matrix materials such as those used in pultrusion. That is, depending on the binder solution, the silane applied to the fiberglass will vary.

In order to evaluate the benefits of different coating compositions as matrix materials, it is necessary to know their physical properties. Table 3 therefore provides a summary of the desired physical properties.

Table ■ Physical properties of matrix materials Properties Viscosity at desired value 38C (CP) 1000-1800 Glass transition temperature, T, (C) >100
Rubber state longitudinal thermal expansion coefficient ("rubbery") fXlo-/
r) <150' - Coefficient of longitudinal thermal expansion in glassy state (αg
lassy) (XiO'/r) < 50 cosine θ (on glass) >0.94
0 (degree) ,, <20 balanced bullet 1 raw coefficient, Eeq (Gpa)'>0.0623t
In l', p, jQ tensile coefficient, "Tangent (
Gpa) n1 growth (ch) >
1.0 Next, these are necessary f! 1: I will explain the reason.

■ The viscosity range obtained provides optimal impregnation and
The key is to reduce the air trapping phenomenon.

2 To minimize shrinkage during subsequent high temperature treatment, 100
A glass transition temperature of C or higher is desirable. For example, a composite reinforcement member may be coated with a 11 DPE cable sheath. ) However, this requirement does not apply in the case of very tightly cross-linked materials, such as those in the shaded area of FIG. 3, which exhibit no appreciable elastic change at the glass transition temperature.

3 The coefficient of thermal expansion α in the longitudinal direction of the matrix must be such that the matrix material does not significantly contribute to the properties of the composite.If the glass transition temperature is above the ambient temperature range, the lowest α Table 3 shows the glass state (αglass) and rubber state (αru
bber) expansion rate is shown.

4 The wetting properties of a liquid are best expressed by its surface tension, but the spreadability of a liquid on a given surface can be expressed as the contact angle θ formed between a liquid and a solid. In the case of a liquid system, the power θ is inversely proportional to the surface tension of the liquid. Therefore, when CX5O approaches 1 and θ is 0,
The closer you get to , the easier it becomes to form a solid. The values of θ shown in the table are from RameHart, Inc.
) A-100 type contact goniometer (Contact G
Onimeter Model A-100), the liquid was dropped onto a glass plate under room temperature (20C) equilibrium conditions.

5 Similarly, in order to maintain rigidity during cable wiring at the upper limit of the surrounding attitude (90r), it is desirable to increase the equilibrium elastic modulus Eeq.

6 In order to maintain high rigidity, it is necessary to increase the tangential tensile elastic modulus E tangent at room temperature.

7 The final elongation of the matrix must be greater than the desired service strain, which is about 1 percent for typical fiber optic cable applications.

8 To prevent degassing in the exterior packaging, weight loss must be minimized.

A coating having the ratio shown in the shaded area of FIG. 3 meets the above requirements.

The coating is cured by ultraviolet light that excites the photoinitiator, which is a component of the formulation. When excited, the photopolymerization initiator generates radicals that initiate free radical polymerization, and the coating is crosslinked (cured). Curing is influenced by the reactivity of the components, the amount of light absorbed by the photoinitiator depending on the total number of incident light, and the absorption characteristics of the photoinitiator.

In this case, the glass fibers are not transparent to most UV light, so only a small amount of light passes through the center of the fiber bundle. Therefore, during curing, the amount of heat released is proportional to the amount of reaction.

Since complete cure is desired, it is important to avoid rapid cooling of the thermal reaction before the cure is complete.

The matrix material of the present invention achieves high processing speed (thinness and high reactivity). Furthermore, Teflon (TEF) is added to the coating process.
LON) (trademark of DuPont) pulleys are used to avoid rapid cooling.

Fiberglass rovings can be broadly classified into E-glass and S-glass depending on their composition. E-glass is an alkali-borosilicate composition, while S-glass is a magnesia-borosilicate composition.
It is an alumina-silicate composition. S-glass was developed for military use and has about 33 percent higher tensile strength than E-glass, but costs about 10 times more. The cheaper alternative, S-2 glass, is about 3 times the size of E glass.
It is twice as expensive and has the same composition and properties as S-glass, but has different sizing requirements than S-glass and looser quality control requirements than S-glass. E glass is
Owens-Cornin
g (o/C) ) and PP'G,'! ! rt
S glass and S-'2 glass are commercially available from Owen Corning.

0.91 Km/Kq (or 450 yards/l'b
, i.e. yield length to weight ratio of 450) and 2000
E-glass rovings composed of real filaments (16,5 micrometer diameter) have been evaluated by the above manufacturer. The filaments of the roving are stretched and bonded in a flat ribbon shape using a sizing agent. These rovings are approximately as stiff as a single piece of stainless steel wire6
0 pounds/percent) (27,22 kg/percent).

The important properties of these rovings are shown in the table with the KEVLAR-49 yarn.

11th is a schematic diagram of a coating curing device.

To eliminate twisting, pull the roving 100 (<5
N), pays out from the outside of the spool 101, and has a large diameter (>10
cm) Pass through the flat grooves of pulleys 102 and 103. The roving is then passed through two fixed horizontal bars 104, 105 to separate and spread the strands. This process reduces air entrapment in the coating and increases resin permeability. It then passes through the coating cup 106 and tie 107. The die organizes the impregnated filament into the desired cross-sectional shape. Good impregnation is obtained. A preferred die is shown in Figure 2 which provides a uniform cross-section of the resulting composite as well as an inverted cross-section which makes the cross-section of the reinforcing member elliptical; The impregnated roving is irradiated with a vertical ultraviolet lamp 109 to undergo a primary curing stage 10.
First hardening is performed in Step 8. The hardening stage 108 has an interior made of Coilzak (Alcoa Co., Ltd.).
) trademark) to give it a mirror finish to increase the reflectance of ultraviolet rays. (15 cm (
The housing is made of 0.02 inch (0.02 inch) thick aluminum.

Finally, the partially cured product is transferred to a 25 cm diameter TEFLON' pulley 110, passed through a secondary curing stage 111, and irradiated with a horizontal ultraviolet lamp 112. The curing stage 111 is composed of a horizontal quartz tube whose lower half is silvered to increase the reflectance of ultraviolet rays. The reason for using two lamps will be explained below. The finished product, matrix impregnated roving (MIR), is wound onto a 15 cm diameter plastic (or metal) reel 113. Adjust the tension using an electromagnetic clutch and brake.

Two curing lamps 109 with different output vectors
．． 112 for through-curing and surface curing. The vertical lamp 109 is a high-pressure mercury-xenon lamp, a Schoffel LXM, with a maximum output of 2.5 KW, with a broad and strong emission line from 310 to 366 nm.
It is 2.5000. :(The absorption rate of the coating is low at 66 nm (absorption rate εm between 320 and 36 Onm)
aX = 100 to 20011 mol cm), so more light is transmitted to the inner layer of the coating, resulting in less curing across the thickness of the impregnated roving when irradiated at these wavelengths.

The minimum amount of light required for primary curing of the matrix material shown in FIG. 3 is 0.2 J/cm2. -Next curing stage 1
The maximum available power output from 08 is 1.0 W/α2, so the maximum linear velocity is 30 meters/min.

The lamp housing is a 5choeffel-Kratos L H152 with a 5.72 cm quartz capacitor, heat sink and reflector. A blower under the lamp draws air through a butterfly valve to cool the housing.

When the intake air from the butterfly valve is reduced, all mercury power lines are energized, keeping the lamp hot during curing. The power igniter for this lamp is a L'PS400 with a rating of 7°KV, DC and 170A.

The lateral lamp 112 has an arc length of 15.2 cm.
Medium pressure 1300W mercury novia (Hanovia)
The lamp is No. 6506A. Because the lamp has a lower gas pressure, it has a higher illuminance at 254 nm than a high-pressure 5choeffel lamp.

Since the absorption rate of the coating is high at 254 nm (ε~20,000), irradiation at this wavelength mainly hardens the surface. The minimum amount of light required for secondary curing of the matrix material in the blurred area/area in Figure 3 is 0.5 J/cm2.
It is. The maximum power consumption from the secondary curing stage 111 is 0.5
W/α2, which gives a maximum linear velocity of 30 meters/min.

About 2000 examples each having a diameter of about 16.5 micrometers
Fiberglass roving (PP) consisting of book filaments
Hybon 20 commercially available from G.
77-450) was coated and cured using the apparatus shown in FIG. The applied coating contained 72 weight percent of resin AC hisphenol-A-cyclycidyl ether cyacrylate), 25 weight percent of diluent I (mixture of penta and cadrabusyl methylene), and 3 weight percent of photoinitiator. It has the formula (equity) of the drug (Dolphin Cure 651). The coating cure rate is limited only by the drive speed capability of the take-up reel, so it can be up to 21 meters/
The minute has been reached. A highly developed composite material is disclosed in U.S. Patent No. 4.
It has been successfully used in place of stainless steel wire in the fiber optic cable described in No. 241,979.

The embodiment has a diameter of approximately 11°9 micrometers. 12,
Aramid loach consisting of 000 filaments (
F.J., 1. Dupont's KEVLAR-49)
was coated at the same monthly rate as in the above example.

The impregnation and curing rate was 7.6 meters/min. This is limited by excessive tension on the take-up reel due to filament fraying, but speeds can be increased to over 20 meters/min with a winding device having high tension.

By using a series of matrix constraints I through (2) shown in Example Table (2), each of about 2
Fiberglass loathing consisting of 1,000 filaments (Corning Glass)
Comp-any's Model 475 50) was impregnated. In Table 3, the composition of each matrix material is shown in weight percent.

Each material was successfully coated and cured at a rate of 21 meters/minute. The resulting composite is substantially void-free and fully cured with the desired mechanical performance.

Microscopic examination of the composite showed that virtually all the filaments were surrounded by coating liquid. Analysis shows that the cured composite has less than 10 weight percent void debris, typically less than 5 weight percent. Void debris of less than 1 weight percent was also achieved. Substantially complete impregnation of the filament bundle in this manner provides a composite with the desired bonding between the filaments and load sharing and other desired properties. Other ingredients can also be used to form the coating. For example, impregnation can be improved by adding one or more surfactants to further reduce the wetting angle. Typical surfactants include fluorinated alkyl esters (for example, 3M Co., Ltd.'s
By using this, the amount of diluent used can be reduced.

In Example 1-, curing was carried out with ultraviolet rays, but other hardening methods were used.
Radioactive rays can also be used. For example, an electron beam could be used, but in this case there is usually no need to include a free radical photoinitiator in the coating. Electron beam irradiation allows for deeper curing (usually about 1 mm) compared to ultraviolet irradiation.

Composites formed by the method of the present invention can be used for purposes other than reinforcing members. For example, optical fiber cable structures are known in which one or more optical fibers are surrounded by a fiberglass reinforcing member. A buffer layer of a material with a low tensile modulus, such as silicon, can be disposed between the optical fiber and the reinforcing member. Such a structure can advantageously be formed by the method of the invention. It is also known that by coating metal filaments it is possible to obtain conductive composites that can be used as electromagnetic shields or conductors for cables. Similarly, carbon filaments can be used as reinforcing members or alone as electromagnetic shields. For example, radiation curable silicones are known; see, for example, US Pat. No. 4,324,575 for radiation curable materials with low tensile modulus. The method of the present invention can be used in conjunction with other coating methods, such as when applying a secondary coating around the composite obtained by the method of the present invention.

All of the above-mentioned applications using the method of the invention fall within the scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a typical coating apparatus implementing the method of the present invention. FIG. 2 is a cross-sectional view of a coated die suitable for carrying out the method of the invention. and FIG. 3 are diagrams showing representative coating component proportions suitable for practicing the method of the present invention. [Explanation of symbols of main parts] 100... Roving 101...
・Die 108... - Next curing stage 109... Vertical ultraviolet lamp 111... Secondary curing stage 112... Horizontal ultraviolet lamp Applicant: Western Electric Company No Incorporated

Claims (1)

Claims: 1. A multifilament composite material comprising the steps of passing a bundle of filaments through a coating means and simultaneously curing the coated portion of the bundle by exposing it to actinic radiation. The method further comprises two steps of substantially surrounding each of the filaments with the coating material by impregnating the bundle with a liquid coating material, and wherein the liquid coating material is diacrylic and diacrylic. a resin selected from the group consisting of methacrylic resins, and at least one component selected to form an equilibrium contact angle of 20 degrees or less with the liquid coating material on the filament; A method for producing a multifilament composite material characterized by: 2% tolerance.A method according to claim 1, characterized in that the liquid coating material forms a polydisperse layer. 3. The method according to claim 1 or 2, wherein the coating material comprises (A) bisphenol-A-diglycidyl ether diacrylate resin,
and optionally, (B) a urethane resin, further comprising (■) a mixture of penta and cadrabucyl methylene gelicol diacrylate, (J) i,10 decamethylene glycol diacrylate, and (6) polyethylene glycol (200 ) at least one diluent selected from the group consisting of dimethacrylates. 4. The method according to claim 3, wherein the ingredients (B), (I), (J), and A-40
to 76.3, B=0 to 33.2, and I+J+=
23.7 to 25.8, and A+B+I+J+=1
A method for producing a multifilament composite material, characterized in that it has a relative heavy snoring ratio of 0.00. 5. A method for producing a multifilament composite material according to any one of claims 1 to 4, characterized in that the filament is a glass filament or an aromatic polyamide filament. 6. A method according to any one of claims 1 to 5, characterized in that the bundle is composed of at least 100 filaments each having a diameter of less than 20 micrometers. A method for producing a multifilament composite material. 7. The method according to any one of claims 1 to 6, characterized in that the multifilament bundle is coated and cured at a linear speed of at least 20 meters/min. Method for manufacturing multifilament composite materials. 8. The method according to any one of claims 1 to 7, wherein the radiation is ultraviolet rays, and the material further comprises a photopolymerization initiator that promotes curing by the radiation. A method for producing a multifilament composite material, characterized by: 9. A method for producing a multifilament composite material according to any one of claims 1 to 8, characterized in that the bundle further constitutes at least one optical fiber. 10 consisting of at least 100 filaments of glass or aromatic polyamide, each having a diameter of 20 micrometers or less, constituting at least one optical fiber, and bispheno-λ-ray A-diglycidyl ether; a diacrylate resin, and optionally a urethane resin, further comprising a mixture of penta and quadrate methylene glycol diacrylate; 1. The filament is impregnated with a liquid coating material consisting of at least one diluent selected from the group consisting of IO decamethylene glycol diacrylate, polyethylene glycol (200) dimethacrylate, and a photoinitiator to promote curing by radiation. substantially surrounding each filament with said coating material, passing said bundle through a coating means, and simultaneously exposing said bundle to actinic radiation, such as ultraviolet light, to expose the coated impregnated portion of said bundle. A multifilament composite material manufactured by a method comprising a curing step.